85 1.8 or 100 F2

I suggest you read this review:
http://www.photozone.d​e …m-lab-test-report--review

The last paragraph says it all:
"The Canon EF 100mm f/2 USM is one of the "can't loose" offers in the Canon lens lineup. It performed almost flawlessly in all tested categories. It's interesting that the figures are marginally better compared to its more popular sister lens (EF 85mm f/1.8 USM). So if you can't or don't want to invest into Canon L glass the EF 100mm f/2 USM is a pretty obvious solution providing similar qualities at a much lower price. Highly recommended! "

The 100 F/2 has slightly better IQ but it is going to be insignificant. To the poster that said the AF is faster on the 85 I don't know that is true.

I use the 100 more than any other lens in my stable. But I didn't make a conscious decision to buy it over the 85. I just found one reasonably priced.

It is just going to get down to what focal length will serve you best. There is no other decision.

I have found them to be basically identical in IQ: http://www.pbase.com/l​ightrules/85v100

I used the 100 f2 for many years, then recently moved to the 85 f1.8. But they are both huge bang for buck lenses. Just go on what FL you want.

85 is a bit more versatile on a crop which is the main reason I chose it (100 would be way too long indoors). It's an amazing lens and I am sure so is the 100. Can't go wrong with either.

was in the same scenario, I was looking at either the 85mm or 100mm but ended up taking the plunge for a 100mm F2 as i have a 5D and absolutely love it so far. Such a sharp lens and very quick focusing. If I was on Crop I would have probably gone for the 85mm.

I had the same dilemma and I ended up going with a 85 for my 7D!